The present invention relates to a high-temperature furnace which is energy efficient and capable of generating heat suitable for manufacture of ceramics, forging of steel and melting glass.
Air usually contains 21 percent oxygen and 79 percent nitrogen and that nitrogen provides no contribution to combustion and hinders the temperature from rising, so that a higher oxygen content results in a higher flame temperature. If the oxygen content is increased from the usual value of 21 percent to somewhere between 23 and 28 percent, the combustion temperature will rise very quickly to a certain level. However, there is no further significant increase in temperature if the oxygen content is increased above 28 percent. Higher flame temperature means a greater difference in temperature between the material to be heated and the flame. Therefore, the amount of calories available for heating increases with such temperature difference and greater energy savings is obtained.
There are several ways of increasing the oxygen content of air. The easiest way is to use an additional oxygen source, but this is costly and requires the utmost care for handling. Another approach involves the use of absorbents such as zeolite. However, the latter has yet to be put into practical use because stabilized operation is not yet guaranteed.
U.S. patent application Ser. No. 331,902 filed Dec. 18, 1981 an assigned to Matsushita Electric Industrial Company, Ltd, discloses an oxygen enriching apparatus having oxygen permeable membranes which are parallel in spaced relationships to allow air to pass therebetween, causing oxygen molecules to selectively pass through the membranes to increase the oxygen content of the air to be utilized.